LiDAR

LiDAR (Light Detection and Ranging) is a remote sensing technology that measures the distance to targets by emitting laser pulses and measuring the time it takes for the pulse to return from the target surface. By combining millions of distance measurements with precise angular positioning, LiDAR produces dense, accurate three-dimensional point clouds.

In heritage documentation, two types of LiDAR are most commonly used: Terrestrial Laser Scanning (TLS), where the scanner is positioned on a tripod and scans its surroundings from a fixed position; and Airborne LiDAR, where a scanner is mounted on an aircraft or drone and captures landscape-scale data.

Key advantages of TLS over photogrammetry for heritage documentation include: better accuracy (1–3 mm typical vs 2–5 mm for photogrammetry at equivalent range); ability to work in low-light or night conditions; denser, more uniform point distributions; and better performance on surfaces that are difficult to photograph (smooth stone, polished metal). Key disadvantages are higher equipment cost and the need to register multiple scans to cover a complete building.